The mechanical strain and disruption characteristics of the knee have been incompletely studied. Using a new, small, Hall effect strain transducer, these characteristics can be accurately determined. The knee, one of the more critical joints needed in sports activities, is prone to myriad mechanical disruptions. Knowledge of how the various ligaments in the knee strain and disrupt can be beneficial in the surgical repair and treatment of injuries and can provide information for the design of equipment or modification of activities for the protection of the knee. Strain patterns in the medial collateral, anterior cruciate, lateral collateral, and posterior cruciate ligaments and knee joint capsule will be mapped during various movements. Disruption of the medial collateral ligaments in amputated specimens will be recorded. Surgical repairs of the medial collateral ligaments will be studied using a stereoradiographic motion evaluation technique. Surgical repairs of the medial collateral ligament according to the techniques of Nicholas, O'Donahue, Steadman, DeHaven, and Slocum will also be evaluated using the strain transducer and stereoradiographic techniques. Optimum anterior cruciate ligament attachment sites will be determined for 10 amputated specimans for the normal range of motion using the stereoradiographic method. Objective surgical recommendations will be made.